Dynamic viscosity of dilute aqueous solutions of poly(acrylic acid) at frequencies of 2–500 kHz

• Published in: Journal of polymer science. Polymer physics edition 1974-06, Vol.12 (6), p.1035-1052
• Main Authors: Okamoto, Hideho, Nakajima, Haruhiko, Wada, Yasaku
• Format: Article
• Language: English
• ISSN: 0098-1273; 1542-9385
• DOI: 10.1002/pol.1974.180120602

The dynamic viscosity of aqueous solutions of poly(acrylic acid) at a polymer concentration of ca. 0.15 g/100 ml has been measured at frequencies from 2 to 500 kHz as a function of degree of polymerization P , degree of neutralization α, and salt (NaCl) concentration C s . Relaxation spectra have been obtained from the dynamic viscosity. The spectra in the short relaxation time region can be approximated by the Zimm theory for the conformational relaxation of nonionic polymers. The maximum relaxation time τ 1 of the Zimm spectra is proportional to P 2 and depends rather moderately on α and C s . Increased deviation is found, however, in the long relaxation time region, in particular for high values of P and α and low values of C s . The major part of the deviation is interpreted in terms of rotational relaxation of a molecule as a whole. The rotational relaxation time τ R is proportional to P 3 and increases with increasing α and decreasing C s . The remaining part of the excess spectra located between τ 1 and τ R is ascribed to the deviation of the conformational relaxation from the Zimm theory arising from ionization of the polymer.